Advanced Micro Devices just increased its share buyback program by $6 billion.When it comes to the semiconductor industry, chances are the top name that comes to mind is Nvidia. For the last two years, investors have been consistently reminded of just how dominant Nvidia's presence is in the world of high-performance chipsets, known as graphics processing units (GPUs).While Advanced Micro Devices (AMD -2.12%) has started to build respectable momentum in the GPU world, the company largely remains in Nvidia's ...